This is the Roto Start Rear Adapter for use on the OS 30VG (P) Monster Truck Engine with the ES Back Plate, OSMG2078. FEATURES: Allows engine to be started with the hand held HPI Roto Start, HPIP8711 Aluminum construction with factory installed brass bushing INCLUDES: Rear Adapter for the HPI Roto Start REQUIRES: Installing at rear of crankcase, order OSMG8685 if backplate screws are required COMMENTS: Only for use on the OS 30VG (P) with the ES Back Plate. Will not work with any other engine. jxs 4/01/08 ir/jxs